Current-saving device



W. J. HAHN.

CURRENT SAVING DEVICE.

APPLICATION FILED IA N,20, I920.

1,377,476. P nted May 10, 1921.

II'Z [F6 William JJYfl/l UNITED STATES PATENT OFFICE.

WILLIAM J'. HAHN, OF PHILADELPHIA, PENNSYLVANIA.

CURRENT-SAVING DEVICE.

Application filed January 20, 1920. Serial No. 352,886.

T 0 all whom may concern:

Be it known that I, WVILLIAM J. HAHN, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in' Current-Saving Devices, of which the following is a specification.

A vast amount of electric current is ordinarily wasted due to the fact that a motorman in operating an electric car, train or other vehicle continues to use the current even after the car has attained sufiicient momentum to carry it at a desirable speed to a certain point.

One object of my invention is to secure a more economical use of the electric current employed for operating electric cars, trains or other vehicles.

Another object is to so make the device of my invention that it can be practically installed at a low cost on electrically operated vehicles of various types.

These objects and other advantageous ends which will be described hereinafter, I attain in the following manner, reference being had to the accompanying drawing in which- The figure of drawing is a diagrammatic representation illustrating my invention.

Referring to the drawing, 1 represents an electric speed controller, such for example as a controller used on trolley cars, and this controller as a part of my invention includes a fiber or other insulating sectoral strip 2. The controller as illustrated is shown developed in a plane, however, it will be understood that this controller is usually made so that a part thereof including contact plates 3 is rotatable by a handle 4L and the plates 3 are arranged at different positions with respect to a series of contacting fingers or shoes 5; the contacting plates being connected to various resistances and are arranged in step formation to supply various amounts of current to the motors of the car as they successively engage with the alined contact shoes 5. The insulating strip 2 is set within a metallic member 6 which is preferably made arcuate in actual use and in my invention two additional contacting fingers 7 and 8 are provided; the finger 8 being arranged at a level to contact with the member 6 but at a different level than the insulating strip 2. The finger 7 is adapted to initially engage the portion 9 of the member 6 and afterward engage the insulating member 2 during the rotation of the handle 4. A trolley 10 or other suitable contacting member for engagement with the feed member or wire 11 is connected through the medium of an arc blowout coil 12, such as commonly used, by a wire 13 to a contact member 14;. An arm 15 has a contact portion 16 thereon and this arm normally is in a position so that the contacts 1 1 and 16 are separated. The construction is such that this position of the arm 15 can be maintained due to gravity or by means of a spring 17 A shunt coil 18 is connected by a wire 19' to the wire 13 as shown at 20. This connection 20 in the present instance is located between the arc blow-out, coil 12 and the trolley 10. The other end of the shunt coil 18 is connected with thevwire 21 which leads to the contacting finger 7 the wires 19 and 21 having a switch 22 interposed therein. The shunt coil 18 has a magnetic core 23 for the purpose of magnetizing said core to attract the arm 15 and thereby cause thecontacts 14 and 16 to engage each, other.

A series coil 24 surrounds the core 23 and has one end electrically connected to the arm 15. The other end of the series coil is connected by a wire 25 to the contacting finger 8. The finger 8 is located-to be initiallyengaged by the metallic member 6 during. the movement of the controller handle and is adapted to continue in engagement with the member 6 even after the member 7 has been moved into engagement with the insulator strip 2. It will be noted that by continuing the movement of the handle 1, the successive engagement of the respective shoes 5 with the plates 3 will cause the cutting out of resistance in the usual manner to increase the amount of electric current used to operate the car.

A switch 26 is preferably employed in case it is desired to cut out the series coil 24:, and an overload circuit breaker 27 is preferably interposed between the trolley 10 and the wire 13; it being noted that the switch 22 is operative if desired to cut out the shunt circuit including the shunt coil 18.

My invention as above described is operative to automatically break the main circuit after the amperage has reached its maximum height and the load has been sufficiently started to carry the car at a desirable speed to a certain point, such for example as when running the car between two transverse streets.

The operation of the device is as follows: When the controller handle a is initially turned, the contact fingers 7 and 8 will be brought in engagement with the member 6. A circuit will then be set up wi hin the shunt coil 18 and the core 23 will be magnetized to attract the arm 15 and thereby cause the contact members 14: and 16 to engage each other. This causes the main flow of electric current through the series coil 24. A continued movement of the controller handle 4c will move the insulator strip 2 into engagement with the finger 7 and thereby open the shunt circuit while the amperage is increasing which naturally occurs due to the starting of the heavy load in the movement of the car, the current then continuing through the series coil as the car runs. After the car has moved to increase its momentum, the amperage naturally falls and the series coil 24 will be consequently weakened until the arm 15 is no longer capable of: being held by the magnetism of the core 23 and said arm 15 will move into a position separating the contact members 14 and 16; therei by cutting out the entire current.

If it is found that the momentum of the car after the above described action is not quite sufficient to carry it to the intended point at the desired speed, the handle 4 can be reversed until the member 7 again contacts with the portion 9 of the member 6, at which time the shunt circuit will again be thrown in and current will be supplied while running with the member 7 on 9.

' It will thus be seen that the device of my invention will automatically break the circuit after the amperage has diminished and the load has been sufiiciently accelerated to carry the car at a desirable speed. v The winding of the coil 24 can be varied to make the device respond to different de-- sired speeds roportionate to loads of the car. However, it will be understood that after the character of the windings or" the coil 24 has been once determined to suit the car or load of the car, it will be unnecessary to vary the windings of this coil during the ordinary operation of the car.

While I have described my invention as taking a particular form, it will be under stood that the various parts of my invention may be changed without departing from the spirit thereof, and hence I do not limit myself to the precise construction set forth, but consider that I am at liberty to make such changes and alterations as fairly come with in the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is l. A device of the character described including a series circuit and a shunt coil adapted to close the series circuit; and means for cutting out the shunt coil while the circuit through the series coil is maintained, said series coil, due to weakening by the lowe 'ing of the amperage, being operative to effect the entire breaking of the circuit therethrough; substantially as described.

2. A device of the character described including a shunt coil having a magnetic core; a series coil surrounding said core; contact members electrically connected. to said series coil and normally automatically separated; controlling means having a portion operative to initially pass current through said shunt coil whereby said core is magnetized and thereby effects engagement of said contact members to bring said series coil in electric circuit; and means forming a part of and operative during the movement ot said 'controlling means to effect said closing of the circuit through the series coil; said controlling means having a part subsequently operative to break the circuit through said shunt coil and, through the medium of said first portion, permitting the current to pass through said series coil until the amperage decreases and thereby weakens said series coil and consequent magnetic power of said core, to permit said first contact members to separate and thereby break the circuit through said series coil; substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

WILLIAM J. HAHN.

Witnesses:

ANNA BENTON, CHAS. E. Forms. 

